In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate group add input before caching
[BUG]
OCFS2_IOC_GROUP_ADD can trigger a BUG_ON in
ocfs2_set_new_buffer_uptodate():
kernel BUG at fs/ocfs2/uptodate.c:509!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:ocfs2_set_new_buffer_uptodate+0x194/0x1e0 fs/ocfs2/uptodate.c:509
Code: ffffe88f 42b9fe4c 89e64889 dfe8b4df
Call Trace:
ocfs2_group_add+0x3f1/0x1510 fs/ocfs2/resize.c:507
ocfs2_ioctl+0x309/0x6e0 fs/ocfs2/ioctl.c:887
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583
x64_sys_call+0x1144/0x26a0 arch/x86/include/generated/asm/syscalls_64.h:17
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x93/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7bbfb55a966d
[CAUSE]
ocfs2_group_add() calls ocfs2_set_new_buffer_uptodate() on a
user-controlled group block before ocfs2_verify_group_and_input()
validates that block number. That helper is only valid for newly
allocated metadata and asserts that the block is not already present in
the chosen metadata cache. The code also uses INODE_CACHE(inode) even
though the group descriptor belongs to main_bm_inode and later journal
accesses use that cache context instead.
[FIX]
Validate the on-disk group descriptor before caching it, then add it to
the metadata cache tracked by INODE_CACHE(main_bm_inode). Keep the
validation failure path separate from the later cleanup path so we only
remove the buffer from that cache after it has actually been inserted.
This keeps the group buffer lifetime consistent across validation,
journaling, and cleanup.
In the Linux kernel, the following vulnerability has been resolved:
ima_fs: Correctly create securityfs files for unsupported hash algos
ima_tpm_chip->allocated_banks[i].crypto_id is initialized to
HASH_ALGO__LAST if the TPM algorithm is not supported. However there
are places relying on the algorithm to be valid because it is accessed
by hash_algo_name[].
On 6.12.40 I observe the following read out-of-bounds in hash_algo_name:
==================================================================
BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440
Read of size 8 at addr ffffffff83e18138 by task swapper/0/1
CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3
Call Trace:
<TASK>
dump_stack_lvl+0x61/0x90
print_report+0xc4/0x580
? kasan_addr_to_slab+0x26/0x80
? create_securityfs_measurement_lists+0x396/0x440
kasan_report+0xc2/0x100
? create_securityfs_measurement_lists+0x396/0x440
create_securityfs_measurement_lists+0x396/0x440
ima_fs_init+0xa3/0x300
ima_init+0x7d/0xd0
init_ima+0x28/0x100
do_one_initcall+0xa6/0x3e0
kernel_init_freeable+0x455/0x740
kernel_init+0x24/0x1d0
ret_from_fork+0x38/0x80
ret_from_fork_asm+0x11/0x20
</TASK>
The buggy address belongs to the variable:
hash_algo_name+0xb8/0x420
Memory state around the buggy address:
ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9
ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9
^
ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9
ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9
==================================================================
Seems like the TPM chip supports sha3_256, which isn't yet in
tpm_algorithms:
tpm tpm0: TPM with unsupported bank algorithm 0x0027
That's TPM_ALG_SHA3_256 == 0x0027 from "Trusted Platform Module 2.0
Library Part 2: Structures", page 51 [1].
See also the related U-Boot algorithms update [2].
Thus solve the problem by creating a file name with "_tpm_alg_<ID>"
postfix if the crypto algorithm isn't initialized.
This is how it looks on the test machine (patch ported to v6.12 release):
# ls -1 /sys/kernel/security/ima/
ascii_runtime_measurements
ascii_runtime_measurements_tpm_alg_27
ascii_runtime_measurements_sha1
ascii_runtime_measurements_sha256
binary_runtime_measurements
binary_runtime_measurements_tpm_alg_27
binary_runtime_measurements_sha1
binary_runtime_measurements_sha256
policy
runtime_measurements_count
violations
[1]: https://trustedcomputinggroup.org/wp-content/uploads/Trusted-Platform-Module-2.0-Library-Part-2-Version-184_pub.pdf
[2]: https://lists.denx.de/pipermail/u-boot/2024-July/558835.html
In the Linux kernel, the following vulnerability has been resolved:
HID: usbhid: fix deadlock in hid_post_reset()
You can build a USB device that includes a HID component
and a storage or UAS component. The components can be reset
only together. That means that hid_pre_reset() and hid_post_reset()
are in the block IO error handling. Hence no memory allocation
used in them may do block IO because the IO can deadlock
on the mutex held while resetting a device and calling the
interface drivers.
Use GFP_NOIO for all allocations in them.
In the Linux kernel, the following vulnerability has been resolved:
bpf, arm64: Fix off-by-one in check_imm signed range check
check_imm(bits, imm) is used in the arm64 BPF JIT to verify that
a branch displacement (in arm64 instruction units) fits into the
signed N-bit immediate field of a B, B.cond or CBZ/CBNZ encoding
before it is handed to the encoder. The macro currently tests for
(imm > 0 && imm >> bits) || (imm < 0 && ~imm >> bits) which admits
values in [-2^N, 2^N) — effectively a signed (N+1)-bit range. A
signed N-bit field only holds [-2^(N-1), 2^(N-1)), so the check
admits one extra bit of range on each side.
In particular, for check_imm19(), values in [2^18, 2^19) slip past
the check but do not fit into the 19-bit signed imm19 field of
B.cond. aarch64_insn_encode_immediate() then masks the raw value
into the 19-bit field, setting bit 18 (the sign bit) and flipping
a forward branch into a backward one. Same class of issue exists
for check_imm26() and the B/BL encoding. Shift by (bits - 1)
instead of bits so the actual signed N-bit range is enforced.
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix af_unix iter deadlock
bpf_iter_unix_seq_show() may deadlock when lock_sock_fast() takes the fast
path and the iter prog attempts to update a sockmap. Which ends up spinning
at sock_map_update_elem()'s bh_lock_sock():
WARNING: possible recursive locking detected
test_progs/1393 is trying to acquire lock:
ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: sock_map_update_elem+0xdb/0x1f0
but task is already holding lock:
ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: __lock_sock_fast+0x37/0xe0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(slock-AF_UNIX);
lock(slock-AF_UNIX);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by test_progs/1393:
#0: ffff88814b59c790 (&p->lock){+.+.}-{4:4}, at: bpf_seq_read+0x59/0x10d0
#1: ffff88811ec25fd8 (sk_lock-AF_UNIX){+.+.}-{0:0}, at: bpf_seq_read+0x42c/0x10d0
#2: ffff88811ec25f58 (slock-AF_UNIX){+...}-{3:3}, at: __lock_sock_fast+0x37/0xe0
#3: ffffffff85a6a7c0 (rcu_read_lock){....}-{1:3}, at: bpf_iter_run_prog+0x51d/0xb00
Call Trace:
dump_stack_lvl+0x5d/0x80
print_deadlock_bug.cold+0xc0/0xce
__lock_acquire+0x130f/0x2590
lock_acquire+0x14e/0x2b0
_raw_spin_lock+0x30/0x40
sock_map_update_elem+0xdb/0x1f0
bpf_prog_2d0075e5d9b721cd_dump_unix+0x55/0x4f4
bpf_iter_run_prog+0x5b9/0xb00
bpf_iter_unix_seq_show+0x1f7/0x2e0
bpf_seq_read+0x42c/0x10d0
vfs_read+0x171/0xb20
ksys_read+0xff/0x200
do_syscall_64+0x6b/0x3a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix af_unix null-ptr-deref in proto update
unix_stream_connect() sets sk_state (`WRITE_ONCE(sk->sk_state,
TCP_ESTABLISHED)`) _before_ it assigns a peer (`unix_peer(sk) = newsk`).
sk_state == TCP_ESTABLISHED makes sock_map_sk_state_allowed() believe that
socket is properly set up, which would include having a defined peer. IOW,
there's a window when unix_stream_bpf_update_proto() can be called on
socket which still has unix_peer(sk) == NULL.
CPU0 bpf CPU1 connect
-------- ------------
WRITE_ONCE(sk->sk_state, TCP_ESTABLISHED)
sock_map_sk_state_allowed(sk)
...
sk_pair = unix_peer(sk)
sock_hold(sk_pair)
sock_hold(newsk)
smp_mb__after_atomic()
unix_peer(sk) = newsk
BUG: kernel NULL pointer dereference, address: 0000000000000080
RIP: 0010:unix_stream_bpf_update_proto+0xa0/0x1b0
Call Trace:
sock_map_link+0x564/0x8b0
sock_map_update_common+0x6e/0x340
sock_map_update_elem_sys+0x17d/0x240
__sys_bpf+0x26db/0x3250
__x64_sys_bpf+0x21/0x30
do_syscall_64+0x6b/0x3a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Initial idea was to move peer assignment _before_ the sk_state update[1],
but that involved an additional memory barrier, and changing the hot path
was rejected.
Then a NULL check during proto update in unix_stream_bpf_update_proto() was
considered[2], but the follow-up discussion[3] focused on the root cause,
i.e. sockmap update taking a wrong lock. Or, more specifically, missing
unix_state_lock()[4].
In the end it was concluded that teaching sockmap about the af_unix locking
would be unnecessarily complex[5].
Complexity aside, since BPF_PROG_TYPE_SCHED_CLS and BPF_PROG_TYPE_SCHED_ACT
are allowed to update sockmaps, sock_map_update_elem() taking the unix
lock, as it is currently implemented in unix_state_lock():
spin_lock(&unix_sk(s)->lock), would be problematic. unix_state_lock() taken
in a process context, followed by a softirq-context TC BPF program
attempting to take the same spinlock -- deadlock[6].
This way we circled back to the peer check idea[2].
[1]: https://lore.kernel.org/netdev/ba5c50aa-1df4-40c2-ab33-a72022c5a32e@rbox.co/
[2]: https://lore.kernel.org/netdev/20240610174906.32921-1-kuniyu@amazon.com/
[3]: https://lore.kernel.org/netdev/7603c0e6-cd5b-452b-b710-73b64bd9de26@linux.dev/
[4]: https://lore.kernel.org/netdev/CAAVpQUA+8GL_j63CaKb8hbxoL21izD58yr1NvhOhU=j+35+3og@mail.gmail.com/
[5]: https://lore.kernel.org/bpf/CAAVpQUAHijOMext28Gi10dSLuMzGYh+jK61Ujn+fZ-wvcODR2A@mail.gmail.com/
[6]: https://lore.kernel.org/bpf/dd043c69-4d03-46fe-8325-8f97101435cf@linux.dev/
Summary of scenarios where af_unix/stream connect() may race a sockmap
update:
1. connect() vs. bpf(BPF_MAP_UPDATE_ELEM), i.e. sock_map_update_elem_sys()
Implemented NULL check is sufficient. Once assigned, socket peer won't
be released until socket fd is released. And that's not an issue because
sock_map_update_elem_sys() bumps fd refcnf.
2. connect() vs BPF program doing update
Update restricted per verifier.c:may_update_sockmap() to
BPF_PROG_TYPE_TRACING/BPF_TRACE_ITER
BPF_PROG_TYPE_SOCK_OPS (bpf_sock_map_update() only)
BPF_PROG_TYPE_SOCKET_FILTER
BPF_PROG_TYPE_SCHED_CLS
BPF_PROG_TYPE_SCHED_ACT
BPF_PROG_TYPE_XDP
BPF_PROG_TYPE_SK_REUSEPORT
BPF_PROG_TYPE_FLOW_DISSECTOR
BPF_PROG_TYPE_SK_LOOKUP
Plus one more race to consider:
CPU0 bpf CPU1 connect
-------- ------------
WRITE_ONCE(sk->sk_state, TCP_ESTABLISHED)
sock_map_sk_state_allowed(sk)
sock_hold(newsk)
smp_mb__after_atomic()
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Take state lock for af_unix iter
When a BPF iterator program updates a sockmap, there is a race condition in
unix_stream_bpf_update_proto() where the `peer` pointer can become stale[1]
during a state transition TCP_ESTABLISHED -> TCP_CLOSE.
CPU0 bpf CPU1 close
-------- ----------
// unix_stream_bpf_update_proto()
sk_pair = unix_peer(sk)
if (unlikely(!sk_pair))
return -EINVAL;
// unix_release_sock()
skpair = unix_peer(sk);
unix_peer(sk) = NULL;
sock_put(skpair)
sock_hold(sk_pair) // UaF
More practically, this fix guarantees that the iterator program is
consistently provided with a unix socket that remains stable during
iterator execution.
[1]:
BUG: KASAN: slab-use-after-free in unix_stream_bpf_update_proto+0x155/0x490
Write of size 4 at addr ffff8881178c9a00 by task test_progs/2231
Call Trace:
dump_stack_lvl+0x5d/0x80
print_report+0x170/0x4f3
kasan_report+0xe4/0x1c0
kasan_check_range+0x125/0x200
unix_stream_bpf_update_proto+0x155/0x490
sock_map_link+0x71c/0xec0
sock_map_update_common+0xbc/0x600
sock_map_update_elem+0x19a/0x1f0
bpf_prog_bbbf56096cdd4f01_selective_dump_unix+0x20c/0x217
bpf_iter_run_prog+0x21e/0xae0
bpf_iter_unix_seq_show+0x1e0/0x2a0
bpf_seq_read+0x42c/0x10d0
vfs_read+0x171/0xb20
ksys_read+0xff/0x200
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Allocated by task 2236:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x63/0x80
kmem_cache_alloc_noprof+0x1d5/0x680
sk_prot_alloc+0x59/0x210
sk_alloc+0x34/0x470
unix_create1+0x86/0x8a0
unix_stream_connect+0x318/0x15b0
__sys_connect+0xfd/0x130
__x64_sys_connect+0x72/0xd0
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Freed by task 2236:
kasan_save_stack+0x30/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x70
__kasan_slab_free+0x47/0x70
kmem_cache_free+0x11c/0x590
__sk_destruct+0x432/0x6e0
unix_release_sock+0x9b3/0xf60
unix_release+0x8a/0xf0
__sock_release+0xb0/0x270
sock_close+0x18/0x20
__fput+0x36e/0xac0
fput_close_sync+0xe5/0x1a0
__x64_sys_close+0x7d/0xd0
do_syscall_64+0xf7/0x5e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix NULL deref in map_kptr_match_type for scalar regs
Commit ab6c637ad027 ("bpf: Fix a bpf_kptr_xchg() issue with local
kptr") refactored map_kptr_match_type() to branch on btf_is_kernel()
before checking base_type(). A scalar register stored into a kptr
slot has no btf, so the btf_is_kernel(reg->btf) call dereferences
NULL.
Move the base_type() != PTR_TO_BTF_ID guard before any reg->btf
access.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Validate node_id in arena_alloc_pages()
arena_alloc_pages() accepts a plain int node_id and forwards it through
the entire allocation chain without any bounds checking.
Validate node_id before passing it down the allocation chain in
arena_alloc_pages().
In the Linux kernel, the following vulnerability has been resolved:
i3c: master: renesas: Fix memory leak in renesas_i3c_i3c_xfers()
The xfer structure allocated by renesas_i3c_alloc_xfer() was never freed
in the renesas_i3c_i3c_xfers() function. Use the __free(kfree) cleanup
attribute to automatically free the memory when the variable goes out of
scope.
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: prevent uninitialized lcn caused by zero len
syzbot reported a uninit-value in ntfs_iomap_begin [1].
Since runs was not touched yet, run_lookup_entry() immediately fails
and returns false, which makes the value of "*len" 0.
Simultaneously, the new value and err value are also 0, causing the
logic in attr_data_get_block_locked() to jump directly to ok, ultimately
resulting in *lcn being triggered before it is set [1].
In ntfs_iomap_begin(), the check for a 0 value in clen is moved forward
to before updating lcn to avoid this [1].
[1]
BUG: KMSAN: uninit-value in ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825
ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825
iomap_iter+0x9b7/0x1540 fs/iomap/iter.c:110
Local variable lcn created at:
ntfs_iomap_begin+0x15d/0x1460 fs/ntfs3/inode.c:786
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: Fix error pointer dereference
The variable tps->partner is checked for an error pointer and then if it
is, it sends an error message but does not return and then immediately
dereferenced a few lines below:
tps->partner = typec_register_partner(tps->port, &desc);
if (IS_ERR(tps->partner))
dev_warn(tps->dev, "%s: failed to register partnet\n", __func__);
if (desc.identity) {
typec_partner_set_identity(tps->partner);
cd321x->cur_partner_identity = st.partner_identity;
}
Add early return and fix spelling mistake in error message.
Detected by Smatch:
drivers/usb/typec/tipd/core.c:827 cd321x_update_work() error:
'tps->partner' dereferencing possible ERR_PTR()
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: fix missing run load for vcn0 in attr_data_get_block_locked()
When a compressed or sparse attribute has its clusters frame-aligned,
vcn is rounded down to the frame start using cmask, which can result
in vcn != vcn0. In this case, vcn and vcn0 may reside in different
attribute segments.
The code already handles the case where vcn is in a different segment
by loading its runs before allocation. However, it fails to load runs
for vcn0 when vcn0 resides in a different segment than vcn. This causes
run_lookup_entry() to return SPARSE_LCN for vcn0 since its segment was
never loaded into the in-memory run list, triggering the WARN_ON(1).
Fix this by adding a missing check for vcn0 after the existing vcn
segment check. If vcn0 falls outside the current segment range
[svcn, evcn1), find and load the attribute segment containing vcn0
before performing the run lookup.
The following scenario triggers the bug:
attr_data_get_block_locked()
vcn = vcn0 & cmask <- vcn != vcn0 after frame alignment
load runs for vcn segment <- vcn0 segment not loaded!
attr_allocate_clusters() <- allocation succeeds
run_lookup_entry(vcn0) <- vcn0 not in run -> SPARSE_LCN
WARN_ON(1) <- bug fires here!
In the Linux kernel, the following vulnerability has been resolved:
NFSD: fix nfs4_file access extra count in nfsd4_add_rdaccess_to_wrdeleg
In nfsd4_add_rdaccess_to_wrdeleg, if fp->fi_fds[O_RDONLY] is already
set by another thread, __nfs4_file_get_access should not be called
to increment the nfs4_file access count since that was already done
by the thread that added READ access to the file. The extra fi_access
count in nfs4_file can prevent the corresponding nfsd_file from being
freed.
When stopping nfs-server service, these extra access counts trigger a
BUG in kmem_cache_destroy() that shows nfsd_file object remaining on
__kmem_cache_shutdown.
This problem can be reproduced by running the Git project's test
suite over NFS.
In the Linux kernel, the following vulnerability has been resolved:
greybus: raw: fix use-after-free on cdev close
This addresses a use-after-free bug when a raw bundle is disconnected
but its chardev is still opened by an application. When the application
releases the cdev, it causes the following panic when init on free is
enabled (CONFIG_INIT_ON_FREE_DEFAULT_ON=y):
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 139 at lib/refcount.c:28 refcount_warn_saturate+0xd0/0x130
...
Call Trace:
<TASK>
cdev_put+0x18/0x30
__fput+0x255/0x2a0
__x64_sys_close+0x3d/0x80
do_syscall_64+0xa4/0x290
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The cdev is contained in the "gb_raw" structure, which is freed in the
disconnect operation. When the cdev is released at a later time,
cdev_put gets an address that points to freed memory.
To fix this use-after-free, convert the struct device from a pointer to
being embedded, that makes the lifetime of the cdev and of this device
the same. Then, use cdev_device_add, which guarantees that the device
won't be released until all references to the cdev have been released.
Finally, delegate the freeing of the structure to the device release
function, instead of freeing immediately in the disconnect callback.
In the Linux kernel, the following vulnerability has been resolved:
greybus: raw: fix use-after-free if write is called after disconnect
If a user writes to the chardev after disconnect has been called, the
kernel panics with the following trace (with
CONFIG_INIT_ON_FREE_DEFAULT_ON=y):
BUG: kernel NULL pointer dereference, address: 0000000000000218
...
Call Trace:
<TASK>
gb_operation_create_common+0x61/0x180
gb_operation_create_flags+0x28/0xa0
gb_operation_sync_timeout+0x6f/0x100
raw_write+0x7b/0xc7 [gb_raw]
vfs_write+0xcf/0x420
? task_mm_cid_work+0x136/0x220
ksys_write+0x63/0xe0
do_syscall_64+0xa4/0x290
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Disconnect calls gb_connection_destroy, which ends up freeing the
connection object. When gb_operation_sync is called in the write file
operations, its gets a freed connection as parameter and the kernel
panics.
The gb_connection_destroy cannot be moved out of the disconnect
function, as the Greybus subsystem expect all connections belonging to a
bundle to be destroyed when disconnect returns.
To prevent this bug, use a rw lock to synchronize access between write
and disconnect. This guarantees that the write function doesn't try
to use a disconnected connection.
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: terminate the cached volume label after UTF-8 conversion
ntfs_fill_super() loads the on-disk volume label with utf16s_to_utf8s()
and stores the result in sbi->volume.label. The converted label is later
exposed through ntfs3_label_show() using %s, but utf16s_to_utf8s() only
returns the number of bytes written and does not add a trailing NUL.
If the converted label fills the entire fixed buffer,
ntfs3_label_show() can read past the end of sbi->volume.label while
looking for a terminator.
Terminate the cached label explicitly after a successful conversion and
clamp the exact-full case to the last byte of the buffer.
In the Linux kernel, the following vulnerability has been resolved:
platform/x86: dell-wmi-sysman: bound enumeration string aggregation
populate_enum_data() aggregates firmware-provided value-modifier
and possible-value strings into fixed 512-byte struct members.
The current code bounds each individual source string but then
appends every string and separator with raw strcat() and no
remaining-space check.
Switch the aggregation loops to a bounded append helper and
reject enumeration packages whose combined strings do not fit
in the destination buffers.
[ij: add include]
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: core: Fix integer overflow in UNMAP bounds check
sbc_execute_unmap() checks LBA + range does not exceed the device capacity,
but does not guard against LBA + range wrapping around on 64-bit overflow.
Add an overflow check matching the pattern already used for WRITE_SAME in
the same file.
In the Linux kernel, the following vulnerability has been resolved:
um: Fix potential race condition in TLB sync
During the TLB sync, we need to traverse and modify the page table,
so we should hold the page table lock. Since full SMP support for
threads within the same process is still missing, let's disable the
split page table lock for simplicity.
In the Linux kernel, the following vulnerability has been resolved:
clk: spacemit: ccu_mix: fix inverted condition in ccu_mix_trigger_fc()
Fix inverted condition that skips frequency change trigger,
causing kernel panics during cpufreq scaling.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: avoid reading already updated pages during GC
We found the following issue during fuzz testing:
page: refcount:3 mapcount:0 mapping:00000000b6e89c65 index:0x18b2dc pfn:0x161ba9
memcg:f8ffff800e269c00
aops:f2fs_meta_aops ino:2
flags: 0x52880000000080a9(locked|waiters|uptodate|lru|private|zone=1|kasantag=0x4a)
raw: 52880000000080a9 fffffffec6e17588 fffffffec0ccc088 a7ffff8067063618
raw: 000000000018b2dc 0000000000000009 00000003ffffffff f8ffff800e269c00
page dumped because: VM_BUG_ON_FOLIO(folio_test_uptodate(folio))
page_owner tracks the page as allocated
post_alloc_hook+0x58c/0x5ec
prep_new_page+0x34/0x284
get_page_from_freelist+0x2dcc/0x2e8c
__alloc_pages_noprof+0x280/0x76c
__folio_alloc_noprof+0x18/0xac
__filemap_get_folio+0x6bc/0xdc4
pagecache_get_page+0x3c/0x104
do_garbage_collect+0x5c78/0x77a4
f2fs_gc+0xd74/0x25f0
gc_thread_func+0xb28/0x2930
kthread+0x464/0x5d8
ret_from_fork+0x10/0x20
------------[ cut here ]------------
kernel BUG at mm/filemap.c:1563!
folio_end_read+0x140/0x168
f2fs_finish_read_bio+0x5c4/0xb80
f2fs_read_end_io+0x64c/0x708
bio_endio+0x85c/0x8c0
blk_update_request+0x690/0x127c
scsi_end_request+0x9c/0xb8c
scsi_io_completion+0xf0/0x250
scsi_finish_command+0x430/0x45c
scsi_complete+0x178/0x6d4
blk_mq_complete_request+0xcc/0x104
scsi_done_internal+0x214/0x454
scsi_done+0x24/0x34
which is similar to the problem reported by syzbot:
https://syzkaller.appspot.com/bug?extid=3686758660f980b402dc
This case is consistent with the description in commit 9bf1a3f
("f2fs: avoid GC causing encrypted file corrupted"):
Page 1 is moved from blkaddr A to blkaddr B by move_data_block, and after
being written it is marked as uptodate. Then, Page 1 is moved from blkaddr
B to blkaddr C, VM_BUG_ON_FOLIO was triggered in the endio initiated by
ra_data_block.
There is no need to read Page 1 again from blkaddr B, since it has already
been updated. Therefore, avoid initiating I/O in this case.
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix data loss caused by incorrect use of nat_entry flag
Data loss can occur when fsync is performed on a newly created file
(before any checkpoint has been written) concurrently with a checkpoint
operation. The scenario is as follows:
create & write & fsync 'file A' write checkpoint
- f2fs_do_sync_file // inline inode
- f2fs_write_inode // inode folio is dirty
- f2fs_write_checkpoint
- f2fs_flush_merged_writes
- f2fs_sync_node_pages
- f2fs_flush_nat_entries
- f2fs_fsync_node_pages // no dirty node
- f2fs_need_inode_block_update // return false
SPO and lost 'file A'
f2fs_flush_nat_entries() sets the IS_CHECKPOINTED and HAS_LAST_FSYNC
flags for the nat_entry, but this does not mean that the checkpoint has
actually completed successfully. However, f2fs_need_inode_block_update()
checks these flags and incorrectly assumes that the checkpoint has
finished.
The root cause is that the semantics of IS_CHECKPOINTED and
HAS_LAST_FSYNC are only guaranteed after the checkpoint write fully
completes.
This patch modifies f2fs_need_inode_block_update() to acquire the
sbi->node_write lock before reading the nat_entry flags, ensuring that
once IS_CHECKPOINTED and HAS_LAST_FSYNC are observed to be set, the
checkpoint operation has already completed.
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - copy IV using skcipher ivsize
AF_ALG rfc3686-ctr-aes-ccp requests pass an 8-byte IV to the driver.
ccp_aes_complete() restores AES_BLOCK_SIZE bytes into the caller's IV
buffer while RFC3686 skciphers expose an 8-byte IV, so the restore
overruns the provided buffer.
Use crypto_skcipher_ivsize() to copy only the algorithm's IV length.
In the Linux kernel, the following vulnerability has been resolved:
erofs: unify lcn as u64 for 32-bit platforms
As sashiko reported [1], `lcn` was typed as `unsigned long` (or
`unsigned int` sometimes), which is only 32 bits wide on 32-bit
platforms, which causes `(lcn << lclusterbits)` to be truncated
at 4 GiB.
In order to consolidate the logic, just use `u64` consistently
around the codebase.
[1] https://sashiko.dev/r/20260420034612.1899973-1-hsiangkao%40linux.alibaba.com
In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_mirred: fix wrong device for mac_header_xmit check in tcf_blockcast_redir
In tcf_blockcast_redir(), when iterating block ports to redirect
packets to multiple devices, the mac_header_xmit flag is queried
from the wrong device. The loop sends to dev_prev but queries
dev_is_mac_header_xmit(dev) — which is the NEXT device in the
iteration, not the one being sent to.
This causes tcf_mirred_to_dev() to make incorrect decisions about
whether to push or pull the MAC header. When the block contains
mixed device types (e.g., an ethernet veth and a tunnel device),
intermediate devices get the wrong mac_header_xmit flag, leading to
skb header corruption. In the worst case, skb_push_rcsum with an
incorrect mac_len can exhaust headroom and panic.
The last device in the loop is handled correctly (line 365-366 uses
dev_is_mac_header_xmit(dev_prev)), confirming this is a copy-paste
oversight for the intermediate devices.
Fix by using dev_prev instead of dev for the mac_header_xmit query,
consistent with the device actually being sent to.
In the Linux kernel, the following vulnerability has been resolved:
macvlan: fix macvlan_get_size() not reserving space for IFLA_MACVLAN_BC_CUTOFF
macvlan_get_size() does not account for IFLA_MACVLAN_BC_CUTOFF, but
macvlan_fill_info() conditionally includes it when port->bc_cutoff != 1.
This causes nla_put_s32() to fail with -EMSGSIZE when the netlink skb
runs out of space, triggering a WARN_ON in rtnetlink and preventing the
interface from being dumped.
The bug can be reproduced with:
ip link add macvlan0 link eth0 type macvlan mode bridge
ip link set macvlan0 type macvlan bc_cutoff 0
ip -d link show macvlan0 # fails with -EMSGSIZE
The bc_cutoff feature was added in commit 954d1fa1ac93 ("macvlan: Add
netlink attribute for broadcast cutoff"), which added the nla_put_s32()
call in macvlan_fill_info() but missed adding the corresponding
nla_total_size(4) in macvlan_get_size(). A follow-up commit
55cef78c244d ("macvlan: add forgotten nla_policy for
IFLA_MACVLAN_BC_CUTOFF") fixed the missing nla_policy entry but still
did not fix the size calculation.
In the Linux kernel, the following vulnerability has been resolved:
nexthop: fix IPv6 route referencing IPv4 nexthop
syzbot reported a panic [1] [2].
When an IPv6 nexthop is replaced with an IPv4 nexthop, the has_v4 flag
of all groups containing this nexthop is not updated. This is because
nh_group_v4_update is only called when replacing AF_INET to AF_INET6,
but the reverse direction (AF_INET6 to AF_INET) is missed.
This allows a stale has_v4=false to bypass fib6_check_nexthop, causing
IPv6 routes to be attached to groups that effectively contain only AF_INET
members. Subsequent route lookups then call nexthop_fib6_nh() which
returns NULL for the AF_INET member, leading to a NULL pointer
dereference.
Fix by calling nh_group_v4_update whenever the family changes, not just
AF_INET to AF_INET6.
Reproducer:
# AF_INET6 blackhole
ip -6 nexthop add id 1 blackhole
# group with has_v4=false
ip nexthop add id 100 group 1
# replace with AF_INET (no -6), has_v4 stays false
ip nexthop replace id 1 blackhole
# pass stale has_v4 check
ip -6 route add 2001:db8::/64 nhid 100
# panic
ping -6 2001:db8::1
[1] https://syzkaller.appspot.com/bug?id=e17283eb2f8dcf3dd9b47fe6f67a95f71faadad0
[2] https://syzkaller.appspot.com/bug?id=8699b6ae54c9f35837d925686208402949e12ef3
In the Linux kernel, the following vulnerability has been resolved:
net/sched: taprio: fix use-after-free in advance_sched() on schedule switch
In advance_sched(), when should_change_schedules() returns true,
switch_schedules() is called to promote the admin schedule to oper.
switch_schedules() queues the old oper schedule for RCU freeing via
call_rcu(), but 'next' still points into an entry of the old oper
schedule. The subsequent 'next->end_time = end_time' and
rcu_assign_pointer(q->current_entry, next) are use-after-free.
Fix this by selecting 'next' from the new oper schedule immediately
after switch_schedules(), and using its pre-calculated end_time.
setup_first_end_time() sets the first entry's end_time to
base_time + interval when the schedule is installed, so the value
is already correct.
The deleted 'end_time = sched_base_time(admin)' assignment was also
harmful independently: it would overwrite the new first entry's
pre-calculated end_time with just base_time.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free in smb2_open during durable reconnect
In smb2_open, the call to ksmbd_put_durable_fd(fp) drops the reference
to the durable file descriptor early during the durable reconnect
process. If an error occurs subsequently (eg, ksmbd_iov_pin_rsp fails)
or a scavenger accesses the file, it leads to a use-after-free when
accessing fp properties (eg fp->create_time).
Move the single put to the end of the function below err_out2 so fp
stays valid until smb2_open returns.
In the Linux kernel, the following vulnerability has been resolved:
ice: fix double-free of tx_buf skb
If ice_tso() or ice_tx_csum() fail, the error path in
ice_xmit_frame_ring() frees the skb, but the 'first' tx_buf still points
to it and is marked as valid (ICE_TX_BUF_SKB).
'next_to_use' remains unchanged, so the potential problem will
likely fix itself when the next packet is transmitted and the tx_buf
gets overwritten. But if there is no next packet and the interface is
brought down instead, ice_clean_tx_ring() -> ice_unmap_and_free_tx_buf()
will find the tx_buf and free the skb for the second time.
The fix is to reset the tx_buf type to ICE_TX_BUF_EMPTY in the error
path, so that ice_unmap_and_free_tx_buf().
Move the initialization of 'first' up, to ensure it's already valid in
case we hit the linearization error path.
The bug was spotted by AI while I had it looking for something else.
It also proposed an initial version of the patch.
I reproduced the bug and tested the fix by adding code to inject
failures, on a build with KASAN.
I looked for similar bugs in related Intel drivers and did not find any.
In the Linux kernel, the following vulnerability has been resolved:
ice: fix race condition in TX timestamp ring cleanup
Fix a race condition between ice_free_tx_tstamp_ring() and ice_tx_map()
that can cause a NULL pointer dereference.
ice_free_tx_tstamp_ring currently clears the ICE_TX_FLAGS_TXTIME flag
after NULLing the tstamp_ring. This could allow a concurrent ice_tx_map
call on another CPU to dereference the tstamp_ring, which could lead to
a NULL pointer dereference.
CPU A:ice_free_tx_tstamp_ring() | CPU B:ice_tx_map()
--------------------------------|---------------------------------
tx_ring->tstamp_ring = NULL |
| ice_is_txtime_cfg() -> true
| tstamp_ring = tx_ring->tstamp_ring
| tstamp_ring->count // NULL deref!
flags &= ~ICE_TX_FLAGS_TXTIME |
Fix by:
1. Reordering ice_free_tx_tstamp_ring() to clear the flag before
NULLing the pointer, with smp_wmb() to ensure proper ordering.
2. Adding smp_rmb() in ice_tx_map() after the flag check to order the
flag read before the pointer read, using READ_ONCE() for the
pointer, and adding a NULL check as a safety net.
3. Converting tx_ring->flags from u8 to DECLARE_BITMAP() and using
atomic bitops (set_bit(), clear_bit(), test_bit()) for all flag
operations throughout the driver:
- ICE_TX_RING_FLAGS_XDP
- ICE_TX_RING_FLAGS_VLAN_L2TAG1
- ICE_TX_RING_FLAGS_VLAN_L2TAG2
- ICE_TX_RING_FLAGS_TXTIME
In the Linux kernel, the following vulnerability has been resolved:
ice: fix potential NULL pointer deref in error path of ice_set_ringparam()
ice_set_ringparam nullifies tstamp_ring of temporary tx_rings, without
clearing ICE_TX_RING_FLAGS_TXTIME bit.
When ICE_TX_RING_FLAGS_TXTIME is set and the subsequent
ice_setup_tx_ring() call fails, a NULL pointer dereference could happen
in the unwinding sequence:
ice_clean_tx_ring()
-> ice_is_txtime_cfg() == true (ICE_TX_RING_FLAGS_TXTIME is set)
-> ice_free_tx_tstamp_ring()
-> ice_free_tstamp_ring()
-> tstamp_ring->desc (NULL deref)
Clear ICE_TX_RING_FLAGS_TXTIME bit to avoid the potential issue.
Note that this potential issue is found by manual code review.
Compile test only since unfortunately I don't have E830 devices.
In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix possible UAF in icmpv6_rcv()
Caching saddr and daddr before pskb_pull() is problematic
since skb->head can change.
Remove these temporary variables:
- We only access &ipv6_hdr(skb)->saddr and &ipv6_hdr(skb)->daddr
when net_dbg_ratelimited() is called in the slow path.
- Avoid potential future misuse after pskb_pull() call.
In the Linux kernel, the following vulnerability has been resolved:
af_unix: Drop all SCM attributes for SOCKMAP.
SOCKMAP can hide inflight fd from AF_UNIX GC.
When a socket in SOCKMAP receives skb with inflight fd,
sk_psock_verdict_data_ready() looks up the mapped socket and
enqueue skb to its psock->ingress_skb.
Since neither the old nor the new GC can inspect the psock
queue, the hidden skb leaks the inflight sockets. Note that
this cannot be detected via kmemleak because inflight sockets
are linked to a global list.
In addition, SOCKMAP redirect breaks the Tarjan-based GC's
assumption that unix_edge.successor is always alive, which
is no longer true once skb is redirected, resulting in
use-after-free below. [0]
Moreover, SOCKMAP does not call scm_stat_del() properly,
so unix_show_fdinfo() could report an incorrect fd count.
sk_msg_recvmsg() does not support any SCM attributes in the
first place.
Let's drop all SCM attributes before passing skb to the
SOCKMAP layer.
[0]:
BUG: KASAN: slab-use-after-free in unix_del_edges (net/unix/garbage.c:118 net/unix/garbage.c:181 net/unix/garbage.c:251)
Read of size 8 at addr ffff888125362670 by task kworker/56:1/496
CPU: 56 UID: 0 PID: 496 Comm: kworker/56:1 Not tainted 7.0.0-rc7-00263-gb9d8b856689d #3 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014
Workqueue: events sk_psock_backlog
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:122)
print_report (mm/kasan/report.c:379)
kasan_report (mm/kasan/report.c:597)
unix_del_edges (net/unix/garbage.c:118 net/unix/garbage.c:181 net/unix/garbage.c:251)
unix_destroy_fpl (net/unix/garbage.c:317)
unix_destruct_scm (./include/net/scm.h:80 ./include/net/scm.h:86 net/unix/af_unix.c:1976)
sk_psock_backlog (./include/linux/skbuff.h:?)
process_scheduled_works (kernel/workqueue.c:?)
worker_thread (kernel/workqueue.c:?)
kthread (kernel/kthread.c:438)
ret_from_fork (arch/x86/kernel/process.c:164)
ret_from_fork_asm (arch/x86/entry/entry_64.S:258)
</TASK>
Allocated by task 955:
kasan_save_track (mm/kasan/common.c:58 mm/kasan/common.c:78)
__kasan_slab_alloc (mm/kasan/common.c:369)
kmem_cache_alloc_noprof (mm/slub.c:4539)
sk_prot_alloc (net/core/sock.c:2240)
sk_alloc (net/core/sock.c:2301)
unix_create1 (net/unix/af_unix.c:1099)
unix_create (net/unix/af_unix.c:1169)
__sock_create (net/socket.c:1606)
__sys_socketpair (net/socket.c:1811)
__x64_sys_socketpair (net/socket.c:1863 net/socket.c:1860 net/socket.c:1860)
do_syscall_64 (arch/x86/entry/syscall_64.c:?)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
Freed by task 496:
kasan_save_track (mm/kasan/common.c:58 mm/kasan/common.c:78)
kasan_save_free_info (mm/kasan/generic.c:587)
__kasan_slab_free (mm/kasan/common.c:287)
kmem_cache_free (mm/slub.c:6165)
__sk_destruct (net/core/sock.c:2282 net/core/sock.c:2384)
sk_psock_destroy (./include/net/sock.h:?)
process_scheduled_works (kernel/workqueue.c:?)
worker_thread (kernel/workqueue.c:?)
kthread (kernel/kthread.c:438)
ret_from_fork (arch/x86/kernel/process.c:164)
ret_from_fork_asm (arch/x86/entry/entry_64.S:258)
In the Linux kernel, the following vulnerability has been resolved:
sctp: fix OOB write to userspace in sctp_getsockopt_peer_auth_chunks
sctp_getsockopt_peer_auth_chunks() checks that the caller's optval
buffer is large enough for the peer AUTH chunk list with
if (len < num_chunks)
return -EINVAL;
but then writes num_chunks bytes to p->gauth_chunks, which lives
at offset offsetof(struct sctp_authchunks, gauth_chunks) == 8
inside optval. The check is missing the sizeof(struct
sctp_authchunks) = 8-byte header. When the caller supplies
len == num_chunks (for any num_chunks > 0) the test passes but
copy_to_user() writes sizeof(struct sctp_authchunks) = 8 bytes
past the declared buffer.
The sibling function sctp_getsockopt_local_auth_chunks() at the
next line already has the correct check:
if (len < sizeof(struct sctp_authchunks) + num_chunks)
return -EINVAL;
Align the peer variant with its sibling.
Reproducer confirms on v7.0-13-generic: an unprivileged userspace
caller that opens a loopback SCTP association with AUTH enabled,
queries num_chunks with a short optval, then issues the real
getsockopt with len == num_chunks and sentinel bytes painted past
the buffer observes those sentinel bytes overwritten with the
peer's AUTH chunk type. The bytes written are under the peer's
control but land in the caller's own userspace; this is not a
kernel memory corruption, but it is a kernel-side contract
violation that can silently corrupt adjacent userspace data.
In the Linux kernel, the following vulnerability has been resolved:
pppoe: drop PFC frames
RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT
RECOMMENDED for PPPoE. In practice, pppd does not support negotiating
PFC for PPPoE sessions, and the current PPPoE driver assumes an
uncompressed (2-byte) protocol field. However, the generic PPP layer
function ppp_input() is not aware of the negotiation result, and still
accepts PFC frames.
If a peer with a broken implementation or an attacker sends a frame with
a compressed (1-byte) protocol field, the subsequent PPP payload is
shifted by one byte. This causes the network header to be 4-byte
misaligned, which may trigger unaligned access exceptions on some
architectures.
To reduce the attack surface, drop PPPoE PFC frames. Introduce
ppp_skb_is_compressed_proto() helper function to be used in both
ppp_generic.c and pppoe.c to avoid open-coding.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: remove sprintf usage
Replace it with scnprintf, the buffer sizes are expected to be large enough
to hold the result, no need for snprintf+overflow check.
Increase buffer size in mangle_content_len() while at it.
BUG: KASAN: stack-out-of-bounds in vsnprintf+0xea5/0x1270
Write of size 1 at addr [..]
vsnprintf+0xea5/0x1270
sprintf+0xb1/0xe0
mangle_content_len+0x1ac/0x280
nf_nat_sdp_session+0x1cc/0x240
process_sdp+0x8f8/0xb80
process_invite_request+0x108/0x2b0
process_sip_msg+0x5da/0xf50
sip_help_tcp+0x45e/0x780
nf_confirm+0x34d/0x990
[..]
In the Linux kernel, the following vulnerability has been resolved:
netfilter: xtables: restrict several matches to inet family
This is a partial revert of:
commit ab4f21e6fb1c ("netfilter: xtables: use NFPROTO_UNSPEC in more extensions")
to allow ipv4 and ipv6 only.
- xt_mac
- xt_owner
- xt_physdev
These extensions are not used by ebtables in userspace.
Moreover, xt_realm is only for ipv4, since dst->tclassid is ipv4
specific.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nat: use kfree_rcu to release ops
Florian Westphal says:
"Historically this is not an issue, even for normal base hooks: the data
path doesn't use the original nf_hook_ops that are used to register the
callbacks.
However, in v5.14 I added the ability to dump the active netfilter
hooks from userspace.
This code will peek back into the nf_hook_ops that are available
at the tail of the pointer-array blob used by the datapath.
The nat hooks are special, because they are called indirectly from
the central nat dispatcher hook. They are currently invisible to
the nfnl hook dump subsystem though.
But once that changes the nat ops structures have to be deferred too."
Update nf_nat_register_fn() to deal with partial exposition of the hooks
from error path which can be also an issue for nfnetlink_hook.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nfnetlink_osf: fix out-of-bounds read on option matching
In nf_osf_match(), the nf_osf_hdr_ctx structure is initialized once
and passed by reference to nf_osf_match_one() for each fingerprint
checked. During TCP option parsing, nf_osf_match_one() advances the
shared ctx->optp pointer.
If a fingerprint perfectly matches, the function returns early without
restoring ctx->optp to its initial state. If the user has configured
NF_OSF_LOGLEVEL_ALL, the loop continues to the next fingerprint.
However, because ctx->optp was not restored, the next call to
nf_osf_match_one() starts parsing from the end of the options buffer.
This causes subsequent matches to read garbage data and fail
immediately, making it impossible to log more than one match or logging
incorrect matches.
Instead of using a shared ctx->optp pointer, pass the context as a
constant pointer and use a local pointer (optp) for TCP option
traversal. This makes nf_osf_match_one() strictly stateless from the
caller's perspective, ensuring every fingerprint check starts at the
correct option offset.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nfnetlink_osf: fix potential NULL dereference in ttl check
The nf_osf_ttl() function accessed skb->dev to perform a local interface
address lookup without verifying that the device pointer was valid.
Additionally, the implementation utilized an in_dev_for_each_ifa_rcu
loop to match the packet source address against local interface
addresses. It assumed that packets from the same subnet should not see a
decrement on the initial TTL. A packet might appear it is from the same
subnet but it actually isn't especially in modern environments with
containers and virtual switching.
Remove the device dereference and interface loop. Replace the logic with
a switch statement that evaluates the TTL according to the ttl_check.
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_dualpi2: drain both C-queue and L-queue in dualpi2_change()
Fix dualpi2_change() to correctly enforce updated limit and memlimit
values after a configuration change of the dualpi2 qdisc.
Before this patch, dualpi2_change() always attempted to dequeue packets
via the root qdisc (C-queue) when reducing backlog or memory usage, and
unconditionally assumed that a valid skb will be returned. When traffic
classification results in packets being queued in the L-queue while the
C-queue is empty, this leads to a NULL skb dereference during limit or
memlimit enforcement.
This is fixed by first dequeuing from the C-queue path if it is
non-empty. Once the C-queue is empty, packets are dequeued directly from
the L-queue. Return values from qdisc_dequeue_internal() are checked for
both queues. When dequeuing from the L-queue, the parent qdisc qlen and
backlog counters are updated explicitly to keep overall qdisc statistics
consistent.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix durable fd leak on ClientGUID mismatch in durable v2 open
ksmbd_lookup_fd_cguid() returns a ksmbd_file with its refcount
incremented via ksmbd_fp_get(). parse_durable_handle_context() in
the DURABLE_REQ_V2 case properly releases this reference on every
path inside the ClientGUID-match branch, either by calling
ksmbd_put_durable_fd() or by transferring ownership to dh_info->fp
for a successful reconnect. However, when an entry exists in the
global file table with the same CreateGuid but a different
ClientGUID, the code simply falls through to the new-open path
without dropping the reference obtained from ksmbd_lookup_fd_cguid().
Per MS-SMB2 section 3.3.5.9.10 ("Handling the
SMB2_CREATE_DURABLE_HANDLE_REQUEST_V2 Create Context"), the server
MUST locate an Open whose Open.CreateGuid matches the request's
CreateGuid AND whose Open.ClientGuid matches the ClientGuid of the
connection that received the request. If no such Open is found, the
server MUST continue with the normal open execution phase. A
CreateGuid hit with a ClientGUID mismatch is therefore the
"Open not found" case: proceeding with a new open is correct, but
the reference obtained purely as a side effect of the lookup must
not be leaked.
Repeated requests that hit this mismatch pin global_ft entries,
prevent __ksmbd_close_fd() from ever running for the corresponding
files, and defeat the durable scavenger, leading to long-lived
resource leaks.
Release the reference in the mismatch path and clear dh_info->fp so
subsequent logic does not mistake a non-matching lookup result for
a reconnect target.
In the Linux kernel, the following vulnerability has been resolved:
net/rds: zero per-item info buffer before handing it to visitors
rds_for_each_conn_info() and rds_walk_conn_path_info() both hand a
caller-allocated on-stack u64 buffer to a per-connection visitor and
then copy the full item_len bytes back to user space via
rds_info_copy() regardless of how much of the buffer the visitor
actually wrote.
rds_ib_conn_info_visitor() and rds6_ib_conn_info_visitor() only
write a subset of their output struct when the underlying
rds_connection is not in state RDS_CONN_UP (src/dst addr, tos, sl
and the two GIDs via explicit memsets). Several u32 fields
(max_send_wr, max_recv_wr, max_send_sge, rdma_mr_max, rdma_mr_size,
cache_allocs) and the 2-byte alignment hole between sl and
cache_allocs remain as whatever stack contents preceded the visitor
call and are then memcpy_to_user()'d out to user space.
struct rds_info_rdma_connection and struct rds6_info_rdma_connection
are the only rds_info_* structs in include/uapi/linux/rds.h that are
not marked __attribute__((packed)), so they have a real alignment
hole. The other info visitors (rds_conn_info_visitor,
rds6_conn_info_visitor, rds_tcp_tc_info, ...) write all fields of
their packed output struct today and are not known to be vulnerable,
but a future visitor that adds a conditional write-path would have
the same bug.
Reproduction on a kernel built without CONFIG_INIT_STACK_ALL_ZERO=y:
a local unprivileged user opens AF_RDS, sets SO_RDS_TRANSPORT=IB,
binds to a local address on an RDMA-capable netdev (rxe soft-RoCE on
any netdev is sufficient), sendto()'s any peer on the same subnet
(fails cleanly but installs an rds_connection in the global hash in
RDS_CONN_CONNECTING), then calls getsockopt(SOL_RDS,
RDS_INFO_IB_CONNECTIONS). The returned 68-byte item contains 26
bytes of stack garbage including kernel text/data pointers:
0..7 0a 63 00 01 0a 63 00 02 src=10.99.0.1 dst=10.99.0.2
8..39 00 ... gids (memset-zeroed)
40..47 e0 92 a3 81 ff ff ff ff kernel pointer (max_send_wr)
48..55 7f 37 b5 81 ff ff ff ff kernel pointer (rdma_mr_max)
56..59 01 00 08 00 rdma_mr_size (garbage)
60..61 00 00 tos, sl
62..63 00 00 alignment padding
64..67 18 00 00 00 cache_allocs (garbage)
Fix by zeroing the per-item buffer in both rds_for_each_conn_info()
and rds_walk_conn_path_info() before invoking the visitor. This
covers the IPv4/IPv6 IB visitors and hardens all current and future
visitors against the same class of bug.
No functional change for visitors that fully populate their output.
Changes in v2:
- retarget at the net tree (subject prefix "[PATCH net v2]",
net/rds: prefix in the title)
- pick up Reviewed-by tags from Sharath Srinivasan and
Allison Henderson
In the Linux kernel, the following vulnerability has been resolved:
vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting
virtio_transport_init_zcopy_skb() uses iter->count as the size argument
for msg_zerocopy_realloc(), which in turn passes it to
mm_account_pinned_pages() for RLIMIT_MEMLOCK accounting. However, this
function is called after virtio_transport_fill_skb() has already consumed
the iterator via __zerocopy_sg_from_iter(), so on the last skb, iter->count
will be 0, skipping the RLIMIT_MEMLOCK enforcement.
Pass pkt_len (the total bytes being sent) as an explicit parameter to
virtio_transport_init_zcopy_skb() instead of reading the already-consumed
iter->count.
This matches TCP and UDP, which both call msg_zerocopy_realloc() with
the original message size.
In the Linux kernel, the following vulnerability has been resolved:
tipc: fix double-free in tipc_buf_append()
tipc_msg_validate() can potentially reallocate the skb it is validating,
freeing the old one. In tipc_buf_append(), it was being called with a
pointer to a local variable which was a copy of the caller's skb
pointer.
If the skb was reallocated and validation subsequently failed, the error
handling path would free the original skb pointer, which had already
been freed, leading to double-free.
Fix this by checking if head now points to a newly allocated reassembled
skb. If it does, reassign *headbuf for later freeing operations.
In the Linux kernel, the following vulnerability has been resolved:
fs/adfs: validate nzones in adfs_validate_bblk()
Reject ADFS disc records with a zero zone count during boot block
validation, before the disc record is used.
When nzones is 0, adfs_read_map() passes it to kmalloc_array(0, ...)
which returns ZERO_SIZE_PTR, and adfs_map_layout() then writes to
dm[-1], causing an out-of-bounds write before the allocated buffer.
adfs_validate_dr0() already rejects nzones != 1 for old-format
images. Add the equivalent check to adfs_validate_bblk() for
new-format images so that a crafted image with nzones == 0 is
rejected at probe time.
Found by syzkaller.
In the Linux kernel, the following vulnerability has been resolved:
sched/psi: fix race between file release and pressure write
A potential race condition exists between pressure write and cgroup file
release regarding the priv member of struct kernfs_open_file, which
triggers the uaf reported in [1].
Consider the following scenario involving execution on two separate CPUs:
CPU0 CPU1
==== ====
vfs_rmdir()
kernfs_iop_rmdir()
cgroup_rmdir()
cgroup_kn_lock_live()
cgroup_destroy_locked()
cgroup_addrm_files()
cgroup_rm_file()
kernfs_remove_by_name()
kernfs_remove_by_name_ns()
vfs_write() __kernfs_remove()
new_sync_write() kernfs_drain()
kernfs_fop_write_iter() kernfs_drain_open_files()
cgroup_file_write() kernfs_release_file()
pressure_write() cgroup_file_release()
ctx = of->priv;
kfree(ctx);
of->priv = NULL;
cgroup_kn_unlock()
cgroup_kn_lock_live()
cgroup_get(cgrp)
cgroup_kn_unlock()
if (ctx->psi.trigger) // here, trigger uaf for ctx, that is of->priv
The cgroup_rmdir() is protected by the cgroup_mutex, it also safeguards
the memory deallocation of of->priv performed within cgroup_file_release().
However, the operations involving of->priv executed within pressure_write()
are not entirely covered by the protection of cgroup_mutex. Consequently,
if the code in pressure_write(), specifically the section handling the
ctx variable executes after cgroup_file_release() has completed, a uaf
vulnerability involving of->priv is triggered.
Therefore, the issue can be resolved by extending the scope of the
cgroup_mutex lock within pressure_write() to encompass all code paths
involving of->priv, thereby properly synchronizing the race condition
occurring between cgroup_file_release() and pressure_write().
And, if an live kn lock can be successfully acquired while executing
the pressure write operation, it indicates that the cgroup deletion
process has not yet reached its final stage; consequently, the priv
pointer within open_file cannot be NULL. Therefore, the operation to
retrieve the ctx value must be moved to a point *after* the live kn
lock has been successfully acquired.
In another situation, specifically after entering cgroup_kn_lock_live()
but before acquiring cgroup_mutex, there exists a different class of
race condition:
CPU0: write memory.pressure CPU1: write cgroup.pressure=0
=========================== =============================
kernfs_fop_write_iter()
kernfs_get_active_of(of)
pressure_write()
cgroup_kn_lock_live(memory.pressure)
cgroup_tryget(cgrp)
kernfs_break_active_protection(kn)
... blocks on cgroup_mutex
cgroup_pressure_write()
cgroup_kn_lock_live(cgroup.pressure)
cgroup_file_show(memory.pressure, false)
kernfs_show(false)
kernfs_drain_open_files()
cgroup_file_release(of)
kfree(ctx)
of->priv = NULL
cgroup_kn_unlock()
... acquires cgroup_mutex
ctx = of->priv; // may now be NULL
if (ctx->psi.trigger) // NULL dereference
Consequently, there is a possibility that of->priv is NULL, the pressure
write needs to check for this.
Now that the scope of the cgroup_mutex has been expanded, the original
explicit cgroup_get/put operations are no longer necessary, this is
because acquiring/releasing the live kn lock inherently executes a
cgroup get/put operation.
[1]
BUG: KASAN: slab-use-after-free in pressure_write+0xa4/0x210 kernel/cgroup/cgroup.c:4011
Call Trace:
pressure_write+0xa4/0x210 kernel/cgroup/cgroup.c:4011
cgroup_file_write+0x36f/0x790 kernel/cgroup/cgroup.c:43
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
fsnotify: fix inode reference leak in fsnotify_recalc_mask()
fsnotify_recalc_mask() fails to handle the return value of
__fsnotify_recalc_mask(), which may return an inode pointer that needs
to be released via fsnotify_drop_object() when the connector's HAS_IREF
flag transitions from set to cleared.
This manifests as a hung task with the following call trace:
INFO: task umount:1234 blocked for more than 120 seconds.
Call Trace:
__schedule
schedule
fsnotify_sb_delete
generic_shutdown_super
kill_anon_super
cleanup_mnt
task_work_run
do_exit
do_group_exit
The race window that triggers the iref leak:
Thread A (adding mark) Thread B (removing mark)
────────────────────── ────────────────────────
fsnotify_add_mark_locked():
fsnotify_add_mark_list():
spin_lock(conn->lock)
add mark_B(evictable) to list
spin_unlock(conn->lock)
return
/* ---- gap: no lock held ---- */
fsnotify_detach_mark(mark_A):
spin_lock(mark_A->lock)
clear ATTACHED flag on mark_A
spin_unlock(mark_A->lock)
fsnotify_put_mark(mark_A)
fsnotify_recalc_mask():
spin_lock(conn->lock)
__fsnotify_recalc_mask():
/* mark_A skipped: ATTACHED cleared */
/* only mark_B(evictable) remains */
want_iref = false
has_iref = true /* not yet cleared */
-> HAS_IREF transitions true -> false
-> returns inode pointer
spin_unlock(conn->lock)
/* BUG: return value discarded!
* iput() and fsnotify_put_sb_watched_objects()
* are never called */
Fix this by deferring the transition true -> false of HAS_IREF flag from
fsnotify_recalc_mask() (Thread A) to fsnotify_put_mark() (thread B).